/Engine/Source/Runtime/CoreUObject/Public/UObject/CoreRedirects.h
Lock to protect multithreaded access to *KnownMissing functions, which can be called from the async loading threads. TODO: The KnownMissing functions use RedirectTypeMap, which is unguarded; there is race condition vulnerability if asyncloading thread is active before all categories are added to RedirectTypeMap.
static FRWLock KnownMissingLock;